Title: Hydrogen purification with palladium and palladium alloys on porous stainless steel membranes

Authors: James R. Brenner, Gaurav Bhagat, Pareen Vasa

Addresses: Florida Tech Chemical Engineering, National Center for Hydrogen Research, 150 West University Blvd., 210 Olin Engineering Bldg., Melbourne, FL 32901, USA. ' Florida Tech Chemical Engineering, National Center for Hydrogen Research, 150 West University Blvd., 210 Olin Engineering Bldg., Melbourne, FL 32901, USA. ' Florida Tech Chemical Engineering, National Center for Hydrogen Research, 150 West University Blvd., 210 Olin Engineering Bldg., Melbourne, FL 32901, USA

Abstract: Hydrogen purification membranes have been prepared via a simultaneous electroless plating of Pd and Ag on a 0.5 µm media grade Porous Stainless Steel (PSS). Effects of the electroless bath temperature, composition, annealing time and temperature were studied while developing the Pd coating. Very low but measurable N₂ fluxes were seen, ranging from 0.010 to 0.020 cm³/cm²-min at temperatures varying from 300°C to 400°C. As no helium flux was observed, it appears that nitrogen diffused, albeit much more slowly, through the same interstitial sites that hydrogen did. H₂ permeances varying from (1.9–3.1) × 10–2 cm³/cm²-min-Pa^0.5 were recorded between temperatures from 350°C to 550°C. Sievert|s Law was seen to hold true at all temperatures. Short term stability and reproducibility of the H₂ permeance were confirmed. The activation energy (E_d) for H₂ permeance in the Pd-Ag layer was calculated from the permeance data to be 9 ± 1 kJ/mol.

Keywords: hydrogen purification; palladium; membrane; Sievert|s Law; porous stainless steel; palladium alloys; stainless steel membranes; nitrogen diffusion; hydrocarbon fuels; fuel cells.

DOI: 10.1504/IJOGCT.2008.016734

International Journal of Oil, Gas and Coal Technology, 2008 Vol.1 No.1/2, pp.109 - 125

Published online: 18 Jan 2008 *

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